AC-3 joining

DJ_Izumi · Post by **DJ_Izumi** » Wed Jul 28, 2004 4:26 pm

I'm starting up a series of AMV trailers and this time I'm going for the highest quality possible (For once. >.>) This includes the audio taken from the real movie's DVD trailer. What I'd like to do is directly use the AC-3 stream off the DVD with no conversion, but I have to add a section to the front and at the end. I know, I could just decode it all to WAV, edit and mix, then re-encode the final to AC-3 but I don't want to re-encode.

What tool can I use to directly join multiple AC-3 streams? ^^;;;

narcted · Post by **narcted** » Wed Jul 28, 2004 9:21 pm

Ulead Media Studio Pro and Video Studio 8.0 (with a plugin) will recognize and use AC-3.

DJ_Izumi · Post by **DJ_Izumi** » Wed Jul 28, 2004 9:22 pm

I don't need a tool thatw can READ them. I need a tool that can JOIN two streams without re-encoding them. :/

badmartialarts · Post by **badmartialarts** » Wed Jul 28, 2004 9:53 pm

Hrm, I don't think your editing software is gonna leave it as an AC-3 stream anyway (or does Premiere have native AC-3 support, I've never tried it that way). So if you just make it into a .wav and leave it all as a .wav through editing, it's not going to matter much. Just seems that would be easier for convinience's sake. I hope that makes sense, or is in any way helpful....

DJ_Izumi · Post by **DJ_Izumi** » Wed Jul 28, 2004 10:33 pm

I don't care about EDITING with an AC-3. For the sake of editing, I can cut together a WAV version. Ultimatly, I want to export just the video from Premier, and mux in the final AC-3 stream that's been built from 3 other streams afterwards. I know what I'm doing, I just need a tool to do the joining for me.

Maverick-Rubik · Post by **Maverick-Rubik** » Thu Jul 29, 2004 12:41 am

Have you tried with virtualdub?

Go to Audio > WAV source > and rename the extension to .wav (if for whatever reason the file extension is different) and select it in Direct Stream Copy.

Just an idea...

SS5_Majin_Bebi · Post by **SS5_Majin_Bebi** » Thu Jul 29, 2004 3:59 am

Maverick7013 wrote:Have you tried with virtualdub?

Go to Audio > WAV source > and rename the extension to .wav (if for whatever reason the file extension is different) and select it in Direct Stream Copy.

Just an idea...

*cough*WRONG!!*cough*

Changing the extension doesn't change the nature of the audio files encoding. Plus if you were to use a .wav file thru VirtualDub, You would need to select "WAV Audio" as opposed to "Direct Stream Copy". Do your homework before you shoot your mouth off, please.

Izumi - I'm pretty sure that VirtualDub Mod can join AC3 files to AVI files as a "Stream List" action. And also I'm pretty sure that BeSweet can encode to AC3 if you have the right add-on thingies. All you'd have to do is make your beginning and end bumpers, encode their audio to AC3 using BeSweet, attach the audio with VDub Mod, and then do your video, attach the audio to it with VDub Mod as well, then open your first bumper, select "Append AVI Segment" and pick your main video/trailer thingy, choose "Direct Stream Copy" in the "Video" options, save that, then open THAT file, choose "Append" again, pick the end credits thingy, (remembering to do "Direct Stream Copy" again) and save THAT file as your whole video.

This works best if your video encoding is done prior to the appending part. But you have to make sure the video is encoded with the same codec and is the same resolution, otherwise VDub will give you some crap about "Data types do not match" or something. Plus the Audio must also be encoded at the same data rate. You should be able to find out the data rate of the DVD AC3 file thru Power DVD if you just click "Show Information". Also you'll only be able to hear the audio if you have an AC3 decoder that can decode an AC3 stream from an AVI. As AC3 audio is usually decoded from within an MPEG-2 file on the DVD and not an MPEG-4 file (something to do with the way its joined or something, i dunno

) your DVD filters probly wont work. I know they didnt for me.

If you understand all that, I hope it helped, if not, sorry...

DJ_Izumi · Post by **DJ_Izumi** » Thu Jul 29, 2004 7:44 am

2.0 Dolby Digital AC-3 is by standard 192kbps, while 5.1 Dolby is 448kbps.

What I'm doing is a trailer with Moulin Rouge, going to rent the DVD and demux the AC-3 stream from the DVD rather than decode and re-encode it. I figure it'll be a 2.0 192kbps AC-3 stream, doubt the trailer will be surround, but I'll find out soon enough. Since this will be one of few AMV's done in AC-3, I'm going to tack on a short Dolby Digital bumper to the beginning that I have the VOB for (It's like 7 seconds long) So I want to be able to join both AC-3 streams rather than decode and re-encode them. The goal is to achive the highest possible quality... that, and to get to tack the Dolby Digital logo on for sheer gloating purposes. ^^

SS5_Majin_Bebi · Post by **SS5_Majin_Bebi** » Thu Jul 29, 2004 8:42 am

DJ_Izumi wrote:2.0 Dolby Digital AC-3 is by standard 192kbps, while 5.1 Dolby is 448kbps.

What I'm doing is a trailer with Moulin Rouge, going to rent the DVD and demux the AC-3 stream from the DVD rather than decode and re-encode it. I figure it'll be a 2.0 192kbps AC-3 stream, doubt the trailer will be surround, but I'll find out soon enough. Since this will be one of few AMV's done in AC-3, I'm going to tack on a short Dolby Digital bumper to the beginning that I have the VOB for (It's like 7 seconds long) So I want to be able to join both AC-3 streams rather than decode and re-encode them. The goal is to achive the highest possible quality... that, and to get to tack the Dolby Digital logo on for sheer gloating purposes. ^^

Well then, just dump the AC3s to WAV, edit with them (each piece separately) then attach the relevant AC3s to the relevant footage, then join the segments with VDubMod. Easy.